The present invention relates to a pump structure connectable with an aircushion or a bladder. The pump structure is composed of a flexible main body defining a chamber and a valve room, a thin membrane-type check valve and a substrate board having a through hole and a notch. The chamber is reciprocally compressible and decompressible to pump a fluid for inflating the aircushion or bladder.
A pump is used to pump fluid (gas or liquid) into a cushion or a bladder to form an elastic article such as inflatable mattress, inflatable pillow, inflatable toy, cushion pad, etc. When not used, these inflatable articles can be deflated and stored. U.S. Pat. No. 5,144,708, entitled “check valve for fluid bladders” discloses a technique for combining a bladder with an inflation pump. The bladder is composed of an upper sheet body and a lower sheet body, which define two chambers and a fluid passage between the two chambers. The bladder is equipped with a check valve. The check valve includes two layers of plastic membranes with the same length. The two layers of plastic membranes are disposed in the fluid passage to face inner faces of the upper and lower sheet bodies. A shield material is laid on inner surfaces of the plastic membranes. When the plastic membranes are thermally fused with each other, a space is formed, whereby the check valve can extend between the upper and lower sheet bodies. The two layers of plastic membranes define a duct through which a fluid is able to one-way flow from one chamber to the other chamber of the bladder.
U.S. Pat. No. 5,846,063 discloses an air pump device, which can be reciprocally compressed and decompressed to deliver a fluid. The air pump device includes a hard bottom board. A hook-and-loop fastener and a compressible chamber are arranged on the bottom board. A one-way valve and a coupling tube are mounted on one side of the chamber. The one-way valve permits air to one-way flow into the chamber, while the coupling tube permits air to flow out of the chamber. The other end of the coupling tube is disposed in a case. A check valve is disposed in the case opposite to the coupling tube. In addition, a relief valve and an output tube are mounted on the case. The air is output through the coupling tube, the check valve and the case.
The difference between U.S. Pat. No. 5,144,708 and U.S. Pat. No. 5,846,063 is that the check valves are made of different materials and have different structures. Also, the structural designs of the relevant components are different. For example, U.S. Pat. No. 5,144,708 employs a flexible material to form the pump device. Therefore, the pump device is soft, safe and lightweight. Moreover, the pump device has a flat configuration and is easy to fold and carry. Such pump device can be only fixed inside a specific inflatable cushion/bladder or installed on a periphery thereof. That is, such pump device is only applicable to a specific inflatable cushion/bladder adapted to the pump device. Therefore, it is impossible to flexibly use the pump device to inflate any other aircushion or bladder. Accordingly, the application range of such pump device is quite limited. In general, the pump device can be only used to inflate an inflatable mattress, inflatable pillow, cushion pad or the like.
On the other hand, in operation of such pump device, in case the thin membrane-type check valve is incautiously slightly bent, the airflow will be unable to smoothly flow. Under such circumstance, the air passage will be blocked to result in malfunction of the pump device. It is also found that in inflation operation of the pump device, which is made of soft or flexible material, the pump structure is likely to irregularly bend or fold due to pressing of an operator's fingers in different positions and different attitudes. This will affect the inflation efficiency of the pump device or even lead to malfunction of the pump device.
U.S. Pat. No. 5,846,063 employs hard/rigid material to form the air pump. For example, the bottom board, the coupling tube, the check valve and the case are made of hard material. In comparison with U.S. Pat. No. 5,144,708, almost every components of the substantially metal-made air pump device are rigid. In other words, it is impossible to flex the air pump to change its height or volume. Therefore, such air pump has larger height and volume and heavier weight and is inconvenient to carry. However, such air pump is not subject to bending so that it is free from the problem of unsmooth airflow or malfunction. Therefore, such air pump can be more accurately operated and the application range of such air pump is wider. Especially, the air pump has an output tube connectable to some other inflatable products (such as sport implements, sport shoes and bicycle saddles). However, when the substantially metal-made air pump is connected with a sport implement, it should be taken into consideration that the air pump may bound away or detach from the sport implement to damage the same or hurt a user or other persons.
As well known to those skilled in this field, the pump devices or air pumps made of different materials (flexible or rigid materials) and designed with different structures have different advantages and defects respectively. Therefore, there are some issues on the use of these pump devices or air pumps that should be discussed. For example, the safety in use of these pump devices or air pumps must be considered, especially when applied to sport implements. It is not preferred to make the pump device from too many hard/rigid materials. However, in the case that the pump device is made of flexible material and includes thin membrane-type check valve, the pump device is likely to malfunction due to folding and unsmooth airflow as aforesaid. It is critical how to solve the above problems existing in the prior art.
It is therefore tried by the applicant to provide a pump structure to obviate the above problems. The pump structure of the present invention is able to ensure safety in use of the pump device and eliminate the shortcomings existing in the prior art. The pump structure of the present invention has the following characteristics:                1. The fluid passage defined by the thin membrane-type check valve will not be bent in inflation or pressing operation. Therefore, the intake and exhaustion of air will not be affected.        2. The intake and exhaustion of air is achieved by means of opening/closing operation of two thin membranes of the thin membrane-type check valve. The intake and exhaust port of the thin membrane-type are positioned at a sufficient height or with a sufficient space to allow the opening/closing operation. Moreover, even if the pump device is incautiously bent in operation, the variation of the height or space is minimized.        3. The pump device is made of flexible material, which is not too soft. Therefore, the strength of the pump device will not be weakened and thus the pump device is not subject to damage. Also, the bottom of the pump has a sufficient strength for bearing the pressure exerted by an operator's fingers onto the pump device in inflation operation. Therefore, the affection on inflation efficiency of the pump device can be minimized.        4. In the prior art, the thin membrane-type check valve can be hardly applied to those air pumps made of rigid material (as disclosed in U.S. Pat. No. 5,846,063). This is because the thin membrane-type check valve has such a structure that it is impossible to combine the thin membrane-type check valve with the case of the air pump. This problem is solved in the present invention.        